ION BEAM SLOPE CUTTING AS A METHOD FOR 3D MICROSCOPY AND MICROANALYSIS OF LTCC AND OTHER ELECTRONIC STRUCTURES

摘要

The knowledge of the microstructure of thick-film and LTCC components is necessary to understand their electrical properties. This paper presents application of ion beam processing steps in combination with Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analysis for investigation of morphology and chemical composition of various thick-film and LTCC structures and components. The Ion Beam Slope Cutting (IBSC) technique was applied together with ion beam etching and ion beam coating as follows: Cross sectioning through planar structures and surface layers of different materials with an argon ion beam. The plane of the cross-section is defined by the direction of the incident ion beam with a sharp shadow border produced by a screen edge precisely aligned to the sample surface. Additional short selective etching with argon ion beam perpendicular to the surface of the cross section in order to remove redeposited material and to reveal phase or grain boundaries. Coating of the cleaned or etched cross-section surface with a thin AuPd layer to improve the brightness of the SEM image and to avoid electrical charging of insulators during microscopic examination. The ion beam parameters have been optimised experimentally. The successful application of these ion-processing steps for selected microelectronic structures (LTCC thermistors and IC layer and contact systems) have been exemplified on SEM pictures.